Conventional washing machines typically include a suspension system for suspending a wash tub and other components, such as a basket, a motor, and a transmission, within a cabinet and for damping movement of the wash tub and the basket. Known suspension systems include an upper frame and a lower frame. The upper frame is secured to, and supported by, the cabinet. The lower frame is coupled to the upper frame and is movable relative to the upper frame. Typically, the wash tub, basket, motor and transmission are coupled to the lower frame.
Additionally, conventional suspension systems often include suspension rods that extend from the lower frame to the upper frame. Typically, the suspension rods are secured, at their lower ends, to cylinder and piston assemblies mounted to the lower frame so that the lower frame can move relative to the suspension rods, which allows for damping of the wash tub and basket movement. In addition, the suspension rods are typically secured, at their upper ends, to the upper frame. For example, the upper end of each suspension rod is often secured to the upper frame via a plastic ball joint positioned within a corresponding joint cup defined in the upper frame.
To reduce friction between the ball joint and the joint cup and to prevent wear on the joint, the interface between the ball joint and the cup must often be lubricated. For conventional suspension systems, such lubrication must occur prior to the ball joint being assembled within the joint cup. Specifically, assembly workers must typically pre-apply an amount of lubricant within the recess defined by the joint cup. Following the application of lubricant within each joint cup, the ball joint and suspension rod are then assembled relative to the joint cup. Unfortunately, such pre-application of the lubricant typically requires the use of assembly aids or other assembly features to keep other components away from the pre-lubricated joint cup as an the operator assembles the components.
Accordingly, an improved ball joint design for a washing machine suspension system that allows the joint to be lubricated post assembly of the suspension system would be welcomed in the technology.